print,reg,balcmds: list output formats accurately in --help (#689)

Also:
- tweak the unsupported output format message
- Hledger.Cli.CliOptions no longer exports outputflags

hledger/Hledger/Cli/CliOptions.hs

@@ -15,7 +15,7 @@ module Hledger.Cli.CliOptions (
   hiddenflags,
   inputflags,
   reportflags,
-  outputflags,
+  -- outputflags,
   outputFormatFlag,
   outputFileFlag,
   generalflagsgroup1,
@@ -192,9 +192,18 @@ hiddenflags = [
  ]
 
 -- | Common output-related flags: --output-file, --output-format...
-outputflags = [outputFormatFlag, outputFileFlag]
-outputFormatFlag = flagReq  ["output-format","O"] (\s opts -> Right $ setopt "output-format" s opts) "FMT" "select the output format. Supported formats:\ntxt, csv, html."
-outputFileFlag   = flagReq  ["output-file","o"]   (\s opts -> Right $ setopt "output-file" s opts) "FILE" "write output to FILE. A file extension matching one of the above formats selects that format."
+
+-- outputflags = [outputFormatFlag, outputFileFlag]
+
+outputFormatFlag :: [String] -> Flag RawOpts
+outputFormatFlag fmts = flagReq
+  ["output-format","O"] (\s opts -> Right $ setopt "output-format" s opts) "FMT"
+  ("select the output format. Supported formats:\n" ++ intercalate ", " fmts ++ ".")
+
+outputFileFlag :: Flag RawOpts
+outputFileFlag = flagReq
+  ["output-file","o"] (\s opts -> Right $ setopt "output-file" s opts) "FILE"
+  "write output to FILE. A file extension matching one of the above formats selects that format."
 
 argsFlag :: FlagHelp -> Arg RawOpts
 argsFlag desc = flagArg (\s opts -> Right $ setopt "args" s opts) desc

hledger/Hledger/Cli/Commands/Balance.hs

@@ -295,8 +295,9 @@ balancemode = hledgerCommandMode
    ,flagNone ["invert"] (setboolopt "invert") "display all amounts with reversed sign"
    ,flagNone ["transpose"] (setboolopt "transpose") "transpose rows and columns"
    ,flagNone ["percent", "%"] (setboolopt "percent") "express values in percentage of each column's total"
+   ,outputFormatFlag ["txt","html","csv","json"]
+   ,outputFileFlag
    ]
-   ++ outputflags
   )
   [generalflagsgroup1]
   hiddenflags

hledger/Hledger/Cli/Commands/Print.hs

@@ -39,7 +39,9 @@ printmode = hledgerCommandMode
     "show all amounts explicitly"
   ,flagNone ["new"] (setboolopt "new")
     "show only newer-dated transactions added in each file since last run"
-  ] ++ outputflags)
+  ,outputFormatFlag ["txt","csv","json"]
+  ,outputFileFlag
+  ])
   [generalflagsgroup1]
   hiddenflags
   ([], Just $ argsFlag "[QUERY]")

hledger/Hledger/Cli/Commands/Register.hs

@@ -51,7 +51,9 @@ registermode = hledgerCommandMode
 #endif
       ++ " or $COLUMNS). -wN,M sets description width as well."
      )
-  ] ++ outputflags)
+  ,outputFormatFlag ["txt","csv","json"]
+  ,outputFileFlag
+  ])
   [generalflagsgroup1]
   hiddenflags
   ([], Just $ argsFlag "[QUERY]")

hledger/Hledger/Cli/CompoundBalanceCommand.hs

@@ -108,7 +108,7 @@ compoundBalanceCommandMode CompoundBalanceCommandSpec{..} =
     ,flagNone ["pretty-tables"] (setboolopt "pretty-tables") "use unicode when displaying tables"
     ,flagNone ["sort-amount","S"] (setboolopt "sort-amount") "sort by amount instead of account code/name"
     ,flagNone ["percent", "%"] (setboolopt "percent") "express values in percentage of each column's total"
-    ,outputFormatFlag
+    ,outputFormatFlag ["txt","html","csv","json"]
     ,outputFileFlag
     ]
     [generalflagsgroup1]

hledger/Hledger/Cli/Utils.hs

@@ -60,7 +60,7 @@ import Hledger.Utils
 
 -- | Standard error message for a bad output format specified with -O/-o.
 unsupportedOutputFormatError :: String -> String
-unsupportedOutputFormatError fmt = "Sorry, output format \""++fmt++"\" is unrecognised or not yet implemented for this report."
+unsupportedOutputFormatError fmt = "Sorry, output format \""++fmt++"\" is unrecognised or not yet implemented for this report or report mode."
 
 -- | Parse the user's specified journal file(s) as a Journal, maybe apply some
 -- transformations according to options, and run a hledger command with it.